The University of Colorado School of Medicine will purchase a BIAcore 3000 instrument with support from the NCRR Shared Instrumentation Grant program. This biosensor is required to meet the growing demand for characterization of the binding properties and kinetics of biological macromolecules. The increased demand results from expansion of the faculty in several departments in the School, and from the establishment of a new interdepartmental Biomolecular Structure Program. The requested biosensor will vastly improve the existing resources and will accelerate research in the following systems: * Signaling protein interactions downstream of prolactin and integrin receptors (S. Anderson) * Design of peptide-based vaccines and antimicrobial agents (R. S. Hodges) * Epstein-Barr infection and immunoregulation by viral proteins and complement receptors (V. M. Holers) * Enterotoxin, cholera and diptheria toxins interactions with ganglioside receptors (R. K. Holmes) * Coronaviral infection by binding of viral proteins to cell surface receptors (K. V. Holmes) * Signaling in asthma through antigen receptors and kinases (G. Johnson) * T cell receptor interactions with major histocompatibility complexes (B. L. Kotzin) * Endocytosis and signal transduction mediated by intracellular protein domains (M. J. Overduin) * Pathogenesis mediated by interactions of bacterially secreted phospholipases (M. Vasil)